SQL401B - Temporary distributed result table &1 was created while processing grouping criteria

SQL401B
Message Text: Temporary distributed result table &1 was created while processing grouping criteria
Cause Text: A temporary distributed result table was created to contain the intermediate results of the query. Either the query contains grouping columns (GROUP BY) that do not match the partitioning keys of the distributed table or the query contains grouping criteria but no grouping columns were specified.
Recovery Text: For more information about processing of distributed tables, refer to the Distributed Database Programming information.